Additive manufacturing of LiNi1/3Mn1/3Co1/3O2 battery electrode material via vat photopolymerization precursor approach.

Additive manufacturing, also called 3D printing, has the potential to enable the development of flexible, wearable and customizable batteries of any shape, maximizing energy storage while also reducing dead-weight and volume. In this work, for the first time, three-dimensional complex electrode structures of high-energy density LiNi1/3Mn1/3Co1/3O2 (NMC 111) material are developed by means of a vat photopolymerization (VPP) process combined with an innovative precursor approach. This innovative approach involves the solubilization of metal precursor salts into a UV-photopolymerizable resin, so that detrimental light scattering and increased viscosity are minimized, followed by the in-situ synthesis of NMC 111 during thermal post-processing of the printed item. The absence of solid particles within the initial resin allows the production of smaller printed features that are crucial for 3D battery design. The formulation of the UV-photopolymerizable composite resin and 3D printing of complex structures, followed by an optimization of the thermal post-processing yielding NMC 111 is thoroughly described in this study. Based on these results, this work addresses one of the key aspects for 3D printed batteries via a precursor approach: the need for a compromise between electrochemical and mechanical performance in order to obtain fully functional 3D printed electrodes. In addition, it discusses the gaps that limit the multi-material 3D printing of batteries via the VPP process.

Tomato Fruit Nutritional Quality Is Altered by the Foliar Application of Various Metal Oxide Nanomaterials.

Carbohydrates and phytonutrients play important roles in tomato fruit's nutritional quality. In the current study, Fe3O4, MnFe2O4, ZnFe2O4, Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO nanomaterials (NMs) were synthesized, characterized, and applied at 250 mg/L to tomato plants via foliar application to investigate their effects on the nutritional quality of tomato fruits. The plant growth cycle was conducted for a total of 135 days in a greenhouse and the tomato fruits were harvested as they ripened. The lycopene content was initially reduced at 0 stored days by MnFe2O4, ZnFe2O4, and Zn0.5Mn0.5Fe2O4; however, after a 15-day storage, there was no statistical difference between the treatments and the control. Moreover, the ß-carotene content was also reduced by Zn0.5Mn0.5Fe2O4, Mn3O4, and ZnO. The effects of the Mn3O4 and ZnO carried over and inhibited the ß-carotene after the fruit was stored. However, the total phenolic compounds were increased by ZnFe2O4, Zn0.5Mn0.5Fe2O4, and ZnO after 15 days of storage. Additionally, the sugar content in the fruit was enhanced by 118% and 111% when plants were exposed to Mn3O4 and ZnO, respectively. This study demonstrates both beneficial and detrimental effects of various NMs on tomato fruit quality and highlights the need for caution in such nanoscale applications during crop growth.

Lewis Acid Site Assisted Bifunctional Activity of Tin Doped Gallium Oxide and Its Application in Rechargeable Zn-Air Batteries.

The enhanced safety, superior energy, and power density of rechargeable metal-air batteries make them ideal energy storage systems for application in energy grids and electric vehicles. However, the absence of a cost-effective and stable bifunctional catalyst that can replace expensive platinum (Pt)-based catalyst to promote oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) at the air cathode hinders their broader adaptation. Here, it is demonstrated that Tin (Sn) doped ß-gallium oxide (ß-Ga2 O3 ) in the bulk form can efficiently catalyze ORR and OER and, hence, be applied as the cathode in Zn-air batteries. The Sn-doped ß-Ga2 O3 sample with 15% Sn (Snx =0.15 -Ga2 O3 ) displayed exceptional catalytic activity for a bulk, non-noble metal-based catalyst. When used as a cathode, the excellent electrocatalytic bifunctional activity of Snx =0.15 -Ga2 O3 leads to a prototype Zn-air battery with a high-power density of 138 mW cm-2 and improved cycling stability compared to devices with benchmark Pt-based cathode. The combined experimental and theoretical exploration revealed that the Lewis acid sites in ß-Ga2 O3 aid in regulating the electron density distribution on the Sn-doped sites, optimize the adsorption energies of reaction intermediates, and facilitate the formation of critical reaction intermediate (O*), leading to enhanced electrocatalytic activity.

A double-edged effect of manganese-doped graphene quantum dots on salt-stressed Capsicum annuum L.

The objective of the current study is to evaluate both the positive and negative effects of manganese-doped graphene quantum dots (GQD-Mn) on Capsicum annuum L. grown under salt stress. GQD-Mn was synthesized, characterized, and foliar-applied (250 mg/L, 120 mg/L, 60 mg/L) to C. annuum L. before and after the flowering stage, during which 100 mM of NaCl solution was introduced into the soil as salt stress. Controls were designed as absolute control (no nanomaterials or salt) and negative control (no nanomaterials only salt). Herein, we report that GQD-Mn offset the reduction of fruit production in salt-stressed C. annuum L. by around 40 %. However, based on a comprehensive analysis of normal alkanes (n-alkane) using gas chromatography-mass spectrometry (GC-MS), we also observed that the leaf epicuticular wax profile was disturbed by GQD-Mn, as the concentration of long-chain n-alkanes was increased. Meanwhile, the content of magnesium (Mg) and zinc (Zn) indicated a potential promoted photosynthesis activity in C. annuum L leaves. We hypothesize that the optical properties of GQD-Mn allow leaves to utilize light more efficiently, thus improving photosynthetic activities in plants to acclimate salt stress. But the increased light usage also induced heat stress on the leaf surfaces, which caused n-alkanes changes. Our results provided a unique perspective on nano-plant interaction that value both beneficial and toxic effects of nanomaterials, especially when evaluating the safety of nano-enabled agriculture in areas facing harsh environmental conditions such as salinity.

Soil-aged nano titanium dioxide effects on full-grown carrot: Dose and surface-coating dependent improvements on growth and nutrient quality.

Rutile titanium dioxide nanoparticles (nTiO2) were weathered in field soil at 0, 100, 200, and 400 mg Ti/kg soil for four months. Two types of nTiO2 with different surface coatings (hydrophilic and hydrophobic), uncoated nTiO2 (pristine), and the untreated control were included. Thereafter, carrot seeds (Daucus carota L.) were sown in those soils and grown in a growth chamber for 115 days until full maturity. A comparison was made between this and our previous unaged study, where carrots were treated in the same way in soil with freshly amended nTiO2. The responses of plants depended on the nTiO2 surface coating and concentration. The aged hydrophobic and hydrophilic-coated nTiO2 induced more positive effects on plant development at 400 and 100 mg Ti/kg soil, respectively, compared with control and pristine treatments. Taproot and leaf fresh biomass and plant height were improved by up to 64%, 40%, and 40% compared with control, respectively. Meanwhile, nutrient elements such as Fe in leaves, Mg in taproots, and Ca, Zn, and K in roots were enhanced by up to 66%, 64%, 41, 143% and 46%, respectively. However, the contents of sugar, starch, and some other metal elements in taproots were negatively affected, which may compromise their nutritional quality. Taken together, the overall growth of carrots was benefited by the aged nTiO2 depending on coating and concentration. The aging process served as a potential sustainable strategy to alleviate the phytotoxicity of unweathered nanoparticles.

Soil-Weathered CuO Nanoparticles Compromise Foliar Health and Pigment Production in Spinach (Spinacia oleracea).

In this study, spinach plants exposed to fresh/unweathered (UW) or weathered (W) copper compounds in soil were analyzed for growth and nutritional composition. Plants were exposed for 45 days to freshly prepared or soil-aged (35 days) nanoparticulate CuO (nCuO), bulk-scale CuO (bCuO), or CuSO4 at 0 (control), 400, 400, and 40 mg/kg of soil, respectively. Foliar health, gas exchange, pigment content (chlorophyll and carotenoid), catalase and ascorbate peroxidase enzymes, gene expression, and Cu bioaccumulation were evaluated along with SEM imagery for select samples. Foliar biomass was higher in UW control (84%) and in UW ionic treatment (87%), compared to the corresponding W treatments (p ≤ 0.1). Root catalase activity was increased by 110% in UW bCuO treatment as compared to the W counterpart; the value for the W ionic treatment was increased by 2167% compared to the UW counterpart (p ≤ 0.05). At 20 days post-transplantation, W nCuO-exposed plants had ∼56% lower carotenoid content compared to both W control and the UW counterpart (p ≤ 0.05). The findings indicate that over the full life cycle of spinach plant the weathering process significantly deteriorates leaf pigment production under CuO exposure in particular and foliar health in general.

Effects of different surface-coated nTiO2 on full-grown carrot plants: Impacts on root splitting, essential elements, and Ti uptake.

The production and environmental release of surface-modified titanium dioxide nanoparticles (nTiO2) have increased. Hence, crops may be directly exposed to the nTiO2 in soil. In this study, we grew carrots in soils amended with pristine, hydrophilic and hydrophobic surface-coated nTiO2 at 100, 200, and 400 mg kg-1 until full-plant maturity. The content of Ti in plant secondary roots treated with different nTiO2 at 400 mg kg-1 was in the order of hydrophobic > hydrophilic > pristine treatments, with values of 140.1, 100.5, and 64.3 mg kg-1, respectively. The fresh biomass of the taproot was significantly decreased by all nTiO2 forms at 400 mg kg-1 by up to 56 %, compared to control. Pristine nTiO2 at 100 mg kg-1 enhanced the fresh weight of leaves by 51 % with respect to control. Remarkably, an abnormal increase of taproot splitting was found in plants treated with all nTiO2 forms. In carrots treated with the surface-coated nTiO2, the accumulation of Ca, Mg, Fe, and Zn increased in leaves; but Mg, Mn, and Zn decreased in taproots. These results suggest that future regulation of nTiO2 release into soils should consider its surface coating properties since the phytotoxicity effects depend on nTiO2 outer structure.

Antioxidant and defense genetic expressions in corn at early-developmental stage are differentially modulated by copper form exposure (nano, bulk, ionic): Nutrient and physiological effects.

In the present study, Zea mays seedlings grown under nano Cu(OH)2 (nCu), bulk Cu(OH)2 (bCu), and ionic CuSO4 (iCu) compound exposure were harvested after six days. The nutritional profile was determined to be significantly disrupted in the roots by 1000 ppm bCu treatment, resulting in a 58.7% reduction in potassium compared to the control. In the shoots, a significant decrease of manganese was observed for 10 and 1000 ppm iCu treatments with 55.7% and 64.2% reductions, respectively. The overall protein content and catalase (CAT) enzymatic activity, however, remained unaffected in either roots or shoots, while an absence of polyphenol oxidase (PPO) activity was observed for all samples. The genetic expression of defense-related genes, metallothionein (MT), CAT, ascorbate peroxidase (APX), and PPO was assessed. The genetic expression of MT was upregulated 50-fold in roots treated with 1000 ppm bCu. There were no significant differences in CAT transcripts among the various treatments, while APX was upregulated 28 and 19-fold in shoots treated with 10 ppm bCu and 10 ppm nCu, respectively. Meanwhile, APX mRNA levels were downregulated five-fold in shoots treated with 1000 ppm iCu. Thus, indicating that the role of APX in plant defense was reinforced in seedlings exposed to low concentration of particulate Cu compounds. Remarkably, no PPO expression was found in any of the treatments and controls, which suggests this enzyme is expressed only under specific external factors or seedlings have an "immature" cascade signaling activation of the PPO system. Taken together, these results show that bCu and nCu treatments at a low concentration do not compromise vital cell machinery but rather elicit the enhancement of defense responses as observed through the increase in APX expression. Furthermore, under optimal concentrations, these Cu treatments show promise in enhancing corn defense responses, which can ultimately lead to increases in future global crop yields.

Copper nanowires as nanofertilizers for alfalfa plants: Understanding nano-bio systems interactions from microbial genomics, plant molecular responses and spectroscopic studies.

The recent application of nano copper (Cu) compounds in the agrosystem has shown potential to improve the physiological performance and agronomical parameters of crops. We grew alfalfa (Medicago sativa) in potting mix amended with bulk, nano, and ionic Cu compounds at 80 and 280 mg Cu/kg; then, we evaluated plant performance at physiological and molecular levels. Plants treated with bulk/nano Cu presented better agronomical responses. The P and S content was reduced in bulk and ionic Cu-exposed plants, compared to controls (p ≤ .05). All Cu forms increased the content of Fe and Zn in roots and Fe in leaves, compared to controls (p ≤ .05). Leaf-superoxide dismutase expression was augmented ~27-fold and rubisco mRNA was unaffected in bulk/nano Cu-treated plants, compared to controls (p ≤ .05). Bulk/nano Cu incremented the relative abundance of microorganisms involved in the elemental uptake. These results indicate that nano Cu improved the physiology of alfalfa and can be considered as potential nanofertilizers.

Improvement of nutrient elements and allicin content in green onion (Allium fistulosum) plants exposed to CuO nanoparticles.

With the exponential growth of nanomaterial production in the last years, nano copper (Cu)-based compounds are gaining more consideration in agriculture since they can work as pesticides or fertilizers. Chinese scallions (Allium fistulosum), which are characterized by their high content of the antioxidant allicin, were the chosen plants for this study. Spectroscopic and microscopic techniques were used to evaluate the nutrient element, allicin content, and enzyme antioxidant properties of scallion plants. Plants were harvested after growing for 80 days at greenhouse conditions in soil amended with CuO particles [nano (nCuO) and bulk (bCuO)] and CuSO4 at 75-600 mg/kg]. Two-photon microscopy images demonstrated the particulate Cu uptake in nCuO and bCuO treated roots. In plants exposed to 150 mg/kg of the Cu-based compounds, root Cu content was higher in plants treated with nCuO compared with bCuO, CuSO4, and control (p ≤ 0.05). At 150 mg/kg, nCuO increased root Ca (86%), root Fe (71%), bulb Ca (74%), and bulb Mg (108%) content, compared with control (p ≤ 0.05). At the same concentration, bCuO reduced root Ca (67%) and root Mg (33%), compared with control (p ≤ 0.05). At all concentrations, nCuO and CuSO4 increased leaf allicin (56-187% and 42-90%, respectively), compared with control (p ≤ 0.05). The antioxidant enzymes were differentially affected by the Cu-based treatments. Overall, the data showed that nCuO enhances nutrient and allicin contents in scallion, which suggests they might be used as a nanofertilizer for onion production.

Insights into the Biogeochemical Cycling of Cobalt: Precipitation and Transformation of Cobalt Sulfide Nanoparticles under Low-Temperature Aqueous Conditions.

Cobalt sulfide precipitates, key phases in the natural biogeochemistry of cobalt and in relevant remediation and resource recovery processes, are poorly defined under low-temperature aqueous conditions. Here, we systematically studied Co (Fe) sulfides precipitated and aged in environmentally relevant solutions, defined by different combinations of pH, initial cobalt to iron ratios ([Co]aq/[Fe]aq), with/without S0, and the presence/absence of sulfate-reducing bacteria. The initial abiogenic precipitates were composed exclusively of amorphous Co sulfide nanoparticles (CoS·xH2O) that were stable in anoxic solution for 2 months, with estimated log K* values 1-5 orders of magnitude higher than that previously reported for Co sulfides. The addition of S0, in combination with acidic pH and elevated temperature (60 °C), resulted in recrystallization of the amorphous precipitates into nanocrystalline jaipurite (hexagonal CoS) within 1 month. In the presence of Fe(II)aq, the abiogenic precipitates were composed of more crystalline Co sulfides and/or Co-rich mackinawite, the exact phase being dependent on the [Co]aq/[Fe]aq value. The biogenic precipitates displayed higher crystallinity for Co sulfides (up to the formation of nanocrystalline cobalt pentlandite, Co9S8) and lower crystallinity for Co-rich mackinawite, suggestive of mineral-specific bacterial interaction. The revealed precipitation and transformation pathways of Co (Fe) sulfides in this study allows for a better constraint of Co biogeochemistry in various natural and engineered environments.

Nutritional Status of Tomato (Solanum lycopersicum) Fruit Grown in Fusarium-Infested Soil: Impact of Cerium Oxide Nanoparticles.

In this study, the impact of cerium oxide nanoparticles on the nutritional value of tomato (Solanum lycopersicum) fruit grown in soil infested with Fusarium oxysporum f. sp. lycopersici was investigated in a greenhouse pot study. Three-week old seedlings of Bonny Best tomato plants were exposed by foliar and soil routes to nanoparticle CeO2 (NP CeO2) and cerium acetate (CeAc) at 0, 50, and 250 mg/L and transplanted into pots containing a soil mixture infested with the Fusarium wilt pathogen. Fruit biomass, water content, diameter, and nutritional content (lycopene, reducing and total sugar) along with elemental composition, including Ce, were evaluated. Fruit Ce concentration was below the detection limit in all treatments. Foliar exposure to NP CeO2 at 250 increased the fruit dry weight (67%) and lycopene content (9%) in infested plants, compared with the infested untreated control. Foliar exposure to CeAc at 50 mg/L reduced fruit fresh weight (46%) and water content (46%) and increased the fruit lycopene content by 11% via root exposure as compared with the untreated infested control. At 250 mg/L, CeAc increased fruit dry weight (94%), compared with the infested untreated control. Total sugar content decreased in fruits of infested plants exposed via roots to NP CeO2 at 50 mg/kg (63%) and 250 mg/kg (54%), CeAc at 50 mg/kg (46%), and foliarly at 50 mg/L (50%) and 250 mg/L (50%), all compared with the infested untreated control. Plants grown in Fusarium-infested soil had decreased fruit dry weight (42%) and lycopene content (17%) and increased total sugar (60%) and Ca content (140%), when compared with the noninfested untreated control (p ≤ 0.05). Overall, the data suggested minimal negative effects of NP CeO2 on the nutritional value of tomato fruit while simultaneously suppressing Fusarium wilt disease.

Uptake, transport, and effects of nano-copper exposure in zucchini (Cucurbita pepo).

Numerous studies on short term effects of copper-based nanomaterials on plants have been published, however investigations with plants grown in a complex soil medium are lacking. In this study Grey Zucchini (Cucurbita pepo) was grown in an environmental growth chamber using a 1:1 (v/v) potting mix native soil mixture amended with Kocide 3000, nCuO, bCuO, or Cu NPs. After 3 weeks Cu concentrations in the root, stem, and leaves of treated plants were significantly higher than control plants. This increase in Cu concentration did not adversely affect plant growth or chlorophyll production. The activity ascorbate peroxidase (APX) in the roots tissues of plants treated with Kocide 3000, nCuO, and bCuO decreased by at least 45%. Catalase (CAT) activity in root tissues of plants treated with 50 mg/kg of Cu NP decreased by 77%, while those treated at 200 mg/kg were reduced by 80%, compared to controls. The activity of APX and CAT in the leaves of all treated plants remained similar to control plants. Based on the endpoints used in this study, with the exception of a decrease in the accumulation of Zn and B in the roots, the exposure of zucchini to the tested copper compounds resulted in no negative effects.

A comparative metagenomic and spectroscopic analysis of soils from an international point of entry between the US and Mexico.

The Paso del Norte region is characterized by its dynamic industries and active agriculture. Throughout the years, urban and agricultural soils from this region have been exposed to xenobiotics, heavy metals, and excess of hydrocarbons. In this study, samples of urban [domestic workshops (DW)] and agricultural-intended (AI) soils from different sites of Ciudad Juárez, Mexico were evaluated for their fertility, element content, and microbial diversity. Chemical analyses showed that nitrites, nitrates, P, K, Mg, and Mn were predominantly higher in AI soils, compared to DW soils (p ≤ 0.05). The composition of soil microbial communities showed that Proteobacteria phylum was the most abundant in both soils (67%, p ≤ 0.05). In AI soils, Paracoccus denitrificans was reduced (p ≤ 0.05), concurring with an increment in nitrates, while the content of nitrogen was negatively correlated with the rhizobium group (r2 = -0.65, p ≤ 0.05). In DW soils, the Firmicutes phylum represented up to ~25%, and the relative abundance of Proteobacteria strongly correlated with a higher Cu content (r2 = 0.99, p ≤ 0.0001). The monotypic genus Sulfuricurvum was found only in oil-contaminated soil samples. Finally, all samples showed the presence of the recently created phylum Candidatus saccharibacteria. These results describe the productivity parameters of AI soils and its correlation to the microbial diversity, which are very important to understand and potentiate the productivity of soils. The data also suggest that soils impacted with hydrocarbons and metal(oid)s allow the reproduction of microorganisms with the potential to alleviate contaminated sites.

Toxicity of copper hydroxide nanoparticles, bulk copper hydroxide, and ionic copper to alfalfa plants: A spectroscopic and gene expression study.

Bulk Cu compounds such as Cu(OH)2 are extensively used as pesticides in agriculture. Recent investigations suggest that Cu-based nanomaterials can replace bulk materials reducing the environmental impacts of Cu. In this study, stress responses of alfalfa (Medicago sativa L.) seedlings to Cu(OH)2 nanoparticle or compounds were evaluated. Seeds were immersed in suspension/solutions of a Cu(OH)2 nanoform, bulk Cu(OH)2, CuSO4, and Cu(NO3)2 at 25 and 75 mg/L. Six days later, the germination, seedling growth, and the physiological and biochemical responses of sprouts were evaluated. All Cu treatments significantly reduced root elongation (average = 63%). The ionic compounds at 25 and 75 mg/L caused a reduction in all elements analyzed (Ca, K, Mg, P, Zn, and Mn), excepting for S, Fe and Mo. The bulk-Cu(OH)2 treatment reduced K (48%) and P (52%) at 75 mg/L, but increased Zn at 25 (18%) and 75 (21%) mg/L. The nano-Cu(OH)2 reduced K (46%) and P (48%) at 75 mg/L, and also P (37%) at 25 mg/L, compared with control. Confocal microscopy images showed that all Cu compounds, at 75 mg/L, significantly reduced nitric oxide, concurring with the reduction in root growth. Nano Cu(OH)2 at 25 mg/L upregulated the expression of the Cu/Zn superoxide dismutase gene (1.92-fold), while ionic treatments at 75 mg/L upregulated (∼10-fold) metallothionein (MT) transcripts. Results demonstrated that nano and bulk Cu(OH)2 compounds caused less physiological impairments in comparison to the ionic ones in alfalfa seedlings.

ZnO nanoparticles increase photosynthetic pigments and decrease lipid peroxidation in soil grown cilantro (Coriandrum sativum).

The growth of the nanotechnology industry has raised concerns about its environmental impacts. In particular, the effect on terrestrial plants, which are the primary producers of the global food chain, is widely debated. In this study, cilantro plants (Coriandrum sativum) were cultivated for 35 days in soil amended with ZnO nanoparticles (N ZnO), bulk ZnO (B ZnO) and ZnCl2 (ionic/I Zn) at 0-400 mg/kg. Photosynthetic pigments, lipid peroxidation, 1NMR-based metabolic, and ICP-based metallomic profiles were evaluated. All Zn compounds increased the chlorophyll content by at least 50%, compared to control. Only N ZnO at 400 mg/kg decreased lipid peroxidation by 70%. 1NMR data showed that all compounds significantly changed the carbinolic-based compounds, compared with control. Highest root and shoot uptake of Zn was observed at B 400 and I 100, respectively. Results of this study corroborates that N ZnO at a concentration <400 mg/kg improved photosynthesis pigments and the defense response in cilantro plants cultivated in organic soil.

Finding the conditions for the beneficial use of ZnO nanoparticles towards plants-A review.

Zinc oxide nanoparticles (ZnO NPs) have a wide range of applications in cosmetics, electrical, and optical industries. The wide range of applications of ZnO NPs, especially in personal care products, suggest they can reach major environmental matrices causing unforeseen effects. Recent literature has shown conflicting findings regarding the beneficial or detrimental effects of ZnO NPs towards terrestrial biota. In this review we carried out a comprehensive survey about beneficial, as well as detrimental aspects, of the ZnO NPs exposure toward various terrestrial plants. A careful scrutiny of the literature indicates that at low concentrations (about 50 mg/kg), ZnO NPs have beneficial effects on plants. Conversely, at concentrations above 500 mg/kg they may have detrimental effects, unless there is a deficiency of Zn in the growing medium. This review also remarks the critical role of the biotic and abiotic factors that may elevate or ameliorate the impact of ZnO NPs in terrestrial plants.

Plant uptake and translocation of contaminants of emerging concern in soil.

The advent of industrialization has led to the discovery of a wide range of chemicals designed for multiple uses including plant protection. However, after use, most of the chemicals and their derivatives end up in soil and water, interacting with living organisms. Plants, which are primary producers, are intentionally or unintentionally exposed to several chemicals, serving as a vehicle for the transfer of products into the food chain. Although the exposure of pesticides towards plants has been witnessed over a long time in agricultural production, other chemicals have attracted attention very recently. In this review, we carried out a comprehensive overview of the plant uptake capacity of various contaminants of emerging concern (CEC) in soil, such as pesticides, polycyclic aromatic hydrocarbons, perfluorinated compounds, pharmaceutical and personal care products, and engineered nanomaterials. The uptake pathways and overall impacts of these chemicals are highlighted. According to the literature, bioaccumulation of CEC in the root part is higher than in aerial parts. Furthermore, various factors such as plant species, pollutant type, and microbial interactions influence the overall uptake. Lastly, environmental factors such as soil erosion and temperature can also affect the CEC bioavailability towards plants.

Role of Cerium Compounds in Fusarium Wilt Suppression and Growth Enhancement in Tomato ( Solanum lycopersicum).

The use of nanoparticles in plant protection may reduce pesticide usage and contamination and increase food security. In this study, three-week-old Solanum lycopersicum seedlings were exposed, by root or foliar pathways, to CeO2 nanoparticles and cerium acetate at 50 and 250 mg/L prior to transplant into sterilized soil. One week later, the soil was inoculated with the fungal pathogen Fusarium oxysporum f. sp. lycopersici (1 g/kg), and the plants were cultivated to maturity in a greenhouse. Disease severity, biomass/yield, and biochemical and physiological parameters were analyzed in harvested plants. Disease severity was significantly reduced by 250 mg/L of nano-CeO2 and CeAc applied to the soil (53% and 35%, respectively) or foliage (57% and 41%, respectively), compared with non-treated infested controls. Overall, the findings show that nano-CeO2 has potential to suppress Fusarium wilt and improve the chlorophyll content in tomato plants.

Effects of the exposure of TiO2 nanoparticles on basil (Ocimum basilicum) for two generations.

There is a lack of information about the transgenerational effects of titanium dioxide nanoparticles (nano-TiO2) in plants. This study aimed to evaluate the impacts of successive exposure of nano-TiO2 with different surface properties to basil (Ocimum basilicum). Seeds from plants exposed or re-exposed to pristine, hydrophobic, or hydrophilic nano-TiO2 were cultivated for 65 days in soil unamended or amended with 750 mg·kg-1 of the respective particles. Plant growth, concentration of titanium and essential elements, as well as content of carbohydrates and chlorophyll were evaluated. There were no differences on Ti concentration in roots of plants sequentially exposed to pristine or hydrophobic nano-TiO2, or in roots of plants exposed to the corresponding particle, only in the second cycle. However, sequential exposure to hydrophilic particles resulted in 65.2% less Ti in roots, compared to roots of plants exposed the same particles, only in the second cycle. The Ti concentrations in shoots were similar in all treatments. On the other hand, pristine and hydrophilic particles reduced Mg in root by 115% and 81%, respectively, while pristine and hydrophobic particles reduced Ni in shoot by 84% and 75%, respectively, compared to unexposed plants in both cycles. Sequential exposure to pristine nano-TiO2 increased stomatal conductance (214%, p ≤ 0.10), compared to plants that were never exposed. Hydrophobic and hydrophilic nano-TiO2 reduced chlorophyll b (52%) and total chlorophyll (30%) but increased total sugar (186%) and reducing sugar (145%), compared to unexposed plants in both cycles. Sequential exposure to hydrophobic or hydrophilic nano-TiO2 resulted in more adverse effects on photosynthesis but in positive effects on plant growth, compared to pristine nano-TiO2.